OBJECTIVETo deeply explore the effects of microcystins (MC-LR) on Bax and Bcl-2 during the course of MC-LR promoting liver tumor.

METHODSapplied to set up the animal model, and the effect of MC-LR promoting liver tumor was evaluated by the Albertgamma-GT methods. And then, the immunohistochemical technique, RT-PCR and image analysis were used to study the expression of the Bcl-2 and Bax during the course of promoting tumor.

RESULTS(1) MC-LR might enhance the positive reaction rate of GGT. The positive reaction rate of GGT in DEN + pure toxin group was 100%, it was significantly higher than the DEN control group 22.22% (P < 0.05). (2) The intension and areas of the protein expression of Bcl-2 in DEN + pure toxin group were 0.0977 and 0.0315, and in DEN control group were 0.0460 and 0.0205, respectively. The expression level of Bcl-2 protein in DEN + pure toxin group were significantly higher than in DEN control group (P < 0.05). Simultaneously, the protein expression of Bax was significantly decreased by MC-LR (P < 0.05). The intension and areas of the expression of Bax in DEN + pure toxin group were 0.0283 and 0.0073, and in DEN control group were 0.0655 and 0.0244 respectively. (3) The mRNA expression of Bcl-2 was significantly increased by MC-LR. The intension of Bcl-2 mRNA expression in DEN + pure toxin group was 2.244, being significantly higher than in the other groups (P < 0.05). However, the mRNA expression of Bax showed no significant difference between DEN + pure toxin and the other groups.

CONCLUSIONThe expression change of Bcl-2 and Bax should possibly play an important role in the course of MC-LR promoting liver tumor.

Animals ; Apoptosis ; Carcinogens ; toxicity ; Hepatocytes ; metabolism ; Liver Neoplasms ; chemically induced ; metabolism ; Male ; Microcystins ; toxicity ; RNA, Messenger ; genetics ; Rats ; Rats, Wistar ; bcl-2-Associated X Protein ; biosynthesis ; bcl-Associated Death Protein ; biosynthesis

Adult ; Altitude Sickness ; metabolism ; pathology ; Apoptosis ; BH3 Interacting Domain Death Agonist Protein ; metabolism ; Erythroblasts ; cytology ; pathology ; Humans ; Male ; Middle Aged ; RNA, Messenger ; genetics ; bcl-2-Associated X Protein ; metabolism ; bcl-X Protein ; metabolism

PURPOSE: To investigate the anti-tumor effect of capsaicin on human pharyngeal squamous carcinoma cells (FaDu). MATERIALS AND METHODS: The expression of apoptosis/cell cycle-related proteins (or genes) was examined by reverse transcriptase-polymerase chain reaction, western blotting and ELISA methods, while the apoptotic cell population, cell morphology and DNA fragmentation levels were assessed using flow cytometry, fluorescence microscopy and agarose gel electrophoresis. RESULTS: Capsaicin was found to inhibit the growth and proliferation of FaDu cells in a dose- and time-dependent manner. Apoptotic cell death was confirmed by observing increases in nuclear condensation, nuclear DNA fragmentation and sub-G1 DNA content. The observed increase in cytosolic cytochrome c, activation of caspase 3 and PARP (p85) levels following capsaicin treatment indicated that the apoptotic response was mitochondrial pathway-dependent. Gene/protein expression analysis of Bcl-2, Bad and Bax further revealed decreased anti-apoptotic Bcl-2 protein and increased pro-apoptotic Bad/Bax expression. Furthermore, capsaicin suppressed the cell cycle progression at the G1/S phase in FaDu cells by decreasing the expression of the regulators of cyclin B1 and D1, as well as cyclin-dependent protein kinases cdk-1, cdk-2 and cdk-4. CONCLUSION: Our current data show that capsaicin induces apoptosis in FaDu cells and this response is associated with mitochondrial pathways, possibly by mediating cell cycle arrest at G1/S.
Apoptosis/drug effects ; Blotting, Western ; Capsaicin/*pharmacology ; Carcinoma, Squamous Cell/*metabolism ; Cell Cycle/drug effects ; Cell Line, Tumor ; Cell Proliferation/drug effects ; Enzyme-Linked Immunosorbent Assay ; Flow Cytometry ; Humans ; Microscopy, Fluorescence ; Pharyngeal Neoplasms/*metabolism ; Proto-Oncogene Proteins c-bcl-2/genetics/metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; bcl-2-Associated X Protein/genetics/metabolism ; bcl-Associated Death Protein/genetics/metabolism

The purpose of the present study was to explore the seizure-induced changes in Bad (Bcl-2-associated death protein), 14-3-3, phosphoBad, Bcl-2 and Bcl-XL expression in the rat model of focal limbic seizure. Unilateral intra-amygdaloid injection of kainic acid (KA) was made to induce seizure. Electroencephalogram (EEG) and regional cerebral flow (r-CBF) were monitored continuously. Diazepam (30 mg/kg) was administered to terminate the seizure. The apoptotic and surviving neurons in the hippocampus were observed by terminal deoxynucleotidyl transferrase-mediated dUTP nick end labeling (TUNEL) and cresyl violet staining, the expression of Bad, 14-3-3, phosphoBad, Bcl-2 and Bcl-XL were detected with immunofluorescence, Western blot and immunoprecipitation. The results showed that TUNEL-positive neurons appeared at 8 h and reached maximum at 24 h following seizure cessation within the ipsilateral CA3 subfield of the hippocampus. Seizure induced the dephosphorylation of Bad and the dissociation of Bad from its chaperone protein 14-3-3 and subsequent dimerization of Bad with Bcl-XL. The expression of phosphoBad decreased and Bcl-2 increased. There was little change in r-CBF after the seizure. These results suggest that seizure leads to a dephosphorylation of Bad and an upregulation of Bcl-2. Dephosphorylation of Bad may be injurious while the upregulation of Bcl-2 may be protective to the brain damage induced by seizures, but not related with r-CBF.
Amygdala ; physiology ; Animals ; Epilepsies, Partial ; chemically induced ; metabolism ; Hippocampus ; metabolism ; Kainic Acid ; Male ; Microinjections ; Phosphorylation ; Proto-Oncogene Proteins c-bcl-2 ; biosynthesis ; genetics ; Rats ; Up-Regulation ; bcl-Associated Death Protein ; metabolism

OBJECTIVETo investigate the apoptosis-inducing effect of honokiol on human non-Hodgkin lymphoma Raji cells and the possible mechanism.

METHODSRaji cells were treated with different concentrations of honokiol, and the proliferation of the cells was detected using MTT assay. Flow cytometry was employed to analyze the cell cycle changes and apoptosis of honokiol-treated cells. Caspase 8 activity in the cells was measured by caspase 8 kit, and RT-PCR was used to detect the expression of apoptosis-related genes Bcl-2, Bad, and Bax.

RESULTSHonokiol significantly inhibited the growth of Raji cells in a time- and dose-dependent manner, with IC(50) concentration of 17.53, 12.61, and 7.4 µg/ml at 12, 24, 48 h, respectively. Flow cytometry revealed cell cycle arrest at G0/G1 phase following honokiol treatment. The apoptosis rates of Raji cells treated with 7.5 and 15 µg/ml honokiol were significantly higher than that of the control cells [(18.24∓2.53)%, (28.44∓2.48)% vs (4.84∓1.15)%, P<0.01]. Caspase 8 activity in Raji cells was significantly enhanced by honokiol (P<0.05). The mRNA expression of the apoptosis-promoting gene Bad was significantly increased following honokiol treatment (P<0.01), while the expressions of Bcl-2 and Bax remained unchanged.

CONCLUSIONHonokiol can induce apoptosis in Raji cells possibly in relation to enhancement of caspase 8 activity and Bad gene expression.

Antineoplastic Agents, Phytogenic ; pharmacology ; Apoptosis ; drug effects ; Biphenyl Compounds ; pharmacology ; Burkitt Lymphoma ; pathology ; Caspase 8 ; metabolism ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Humans ; Lignans ; pharmacology ; Lymphoma, Non-Hodgkin ; pathology ; bcl-Associated Death Protein ; genetics ; metabolism

OBJECTIVETo observe the sensitivity change of SMMC-7721 cells transfected with antisense DNMT1 gene fragment to tumor necrosis factor related apoptosis inducing ligand (TRAIL) and its mechanism.

METHODSCell survival rate was measured by trypan blue, apoptosis rate by TUNEL method and the expression of bcl-2, bax and bad by flow cytometry.

RESULTSCell survival rate of SMMC-7721 cells transfected with antisense DNMT1 gene fragment was markedly lower than that transfected with sense DNMT1 gene fragment or empty vector (P < 0.05 and 0.01), but the apoptosis rate was on the contrary (P < 0.05 or 0.01). The expression of bax and bad (especially the former), but not bcl-2 of SMMC-7721 cells transfected with antisense DNMT1 gene fragment was markedly higher than those of SMMC-7721 cells transfected with sense DNMT1 gene fragment or empty vector.

CONCLUSIONThe sensitivity of SMMC-7721 cells to TRAIL can be enhanced by the transfection of antisense DNMT1 gene fragment, which may be related to the increase of bax and bad expression.

Antisense Elements (Genetics) ; genetics ; Apoptosis ; drug effects ; Apoptosis Regulatory Proteins ; Carrier Proteins ; analysis ; Cell Line, Tumor ; DNA (Cytosine-5-)-Methyltransferase 1 ; DNA (Cytosine-5-)-Methyltransferases ; antagonists & inhibitors ; genetics ; Flow Cytometry ; Humans ; Liver Neoplasms ; metabolism ; pathology ; Membrane Glycoproteins ; pharmacology ; Proto-Oncogene Proteins ; analysis ; Proto-Oncogene Proteins c-bcl-2 ; TNF-Related Apoptosis-Inducing Ligand ; Tumor Necrosis Factor-alpha ; pharmacology ; bcl-2-Associated X Protein ; bcl-Associated Death Protein

Vorinostat (VOR) has been reported to enhance the cytotoxic effects of doxorubicin (DOX) with fewer side effects because of the lower DOX dosage in breast cancer cells. In this study, we investigated the novel mechanism underlying the synergistic cytotoxic effects of VOR and DOX co-treatment in cervical cancer cells HeLa, CaSki and SiHa cells. Co-treatment with VOR and DOX at marginal doses led to the induction of apoptosis through caspase-3 activation, poly (ADP-ribose) polymerase cleavage and DNA micronuclei. Notably, the synergistic growth inhibition induced by the co-treatment was attributed to the upregulation of the pro-apoptotic protein Bad, as the silencing of Bad expression using small interfering RNA (siRNA) abolished the phenomenon. As siRNA against p53 did not result in an increase in acetylated p53 and the consequent upregulation of Bad, the observed Bad upregulation was mediated by acetylated p53. Moreover, a chromatin immunoprecipitation analysis showed that the co-treatment of HeLa cells with VOR and DOX increased the recruitment of acetylated p53 to the bad promoter, with consequent bad transactivation. Conversely, C33A cervical cancer cells containing mutant p53 co-treated with VOR and DOX did not exhibit Bad upregulation, acetylated p53 induction or consequent synergistic growth inhibition. Together, the synergistic growth inhibition of cervical cancer cell lines induced by co-treatment with VOR and DOX can be attributed to the upregulation of Bad, which is induced by acetylated p53. These results show for the first time that the acetylation of p53, rather than histones, is a mechanism for the synergistic growth inhibition induced by VOR and DOX co-treatments.
Acetylation ; Antineoplastic Agents/*pharmacology ; Apoptosis/drug effects ; Cell Survival/drug effects ; Chromatin/metabolism ; Doxorubicin/*pharmacology ; Drug Synergism ; Female ; HeLa Cells ; Humans ; Hydroxamic Acids/*pharmacology ; Transcriptional Activation ; Tumor Suppressor Protein p53/genetics/*metabolism ; Uterine Cervical Neoplasms/metabolism ; bcl-Associated Death Protein/genetics/*metabolism

An abrupt increase of intracellular Ca2+ is observed in cells under hypoxic or oxidatively stressed conditions. The dysregulated increase of cytosolic Ca2+ triggers apoptotic cell death through mitochondrial swelling and activation of Ca2+-dependent enzymes. Transglutaminase 2 (TG2) is a Ca2+-dependent enzyme that catalyzes transamidation reaction producing cross-linked and polyaminated proteins. TG2 activity is known to be involved in the apoptotic process. However, the pro-apoptotic role of TG2 is still controversial. In this study, we investigate the role of TG2 in apoptosis induced by Ca2+-overload. Overexpression of TG2 inhibited the A23187-induced apoptosis through suppression of caspase-3 and -9 activities, cytochrome c release into cytosol, and mitochondria membrane depolarization. Conversely, down-regulation of TG2 caused the increases of cell death, caspase-3 activity and cytochrome c in cytosol in response to Ca2+-overload. Western blot analysis of Bcl-2 family proteins showed that TG2 reduced the expression level of Bax protein. Moreover, overexpression of Bax abrogated the anti-apoptotic effect of TG2, indicating that TG2-mediated suppression of Bax is responsible for inhibiting cell death under Ca2+-overloaded conditions. Our findings revealed a novel anti-apoptotic pathway involving TG2, and suggested the induction of TG2 as a novel strategy for promoting cell survival in diseases such as ischemia and neurodegeneration.
*Apoptosis ; Apoptosis Regulatory Proteins/metabolism ; Calcimycin/pharmacology ; Calcium/*metabolism ; Caspases/metabolism ; Cell Death ; Cell Survival ; Cytochromes c/metabolism ; Down-Regulation ; GTP-Binding Proteins/*metabolism ; HEK293 Cells ; Hela Cells ; Humans ; Ionophores/pharmacology ; Mitochondria/metabolism ; Transglutaminases/*metabolism ; bcl-2-Associated X Protein/genetics/*metabolism

OBJECTIVETo investigate the effects of Tounongsan () extract (TNSE) on proliferation and apoptosis of the human lymphoma cell line Raji and its possible mechanism of action.

METHODSThe viability of TNSE-treated Raji cells was measured by a 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Cell apoptosis was determined by flow cytometry. The molecular mechanisms of TNSE-mediated apoptosis were further investigated by reverse transcription-polymerase chain reaction (RT-PCR) analysis of the mRNA expression of nuclear factor κB (NF-κB), Bcl-xL, Bcl-2-associated death promoter (Bad), caspase-9 and caspase-3. Western blotting was used to detect the protein expressions of NF-κB, Bad, cleaved caspase-9 and cleaved caspase-3.

RESULTSTNSE inhibited Raji cell proliferation in dose- and time-dependent manners. After 48-h treatment with various concentrations of TNSE (125, 250 and 500 μg/mL), the apoptosis rates of Raji cell were 12.23%±1.98% (P<0.05), 20.97%±3.96% (P<0.01) and 30.4%±4.87% (P<0.01), respectively, compared with those of the control (6.02%±1.01%). RT-PCR demonstrated that NF-κB mRNA expression was significantly downregulated in Raji cells treated with 250 μg/mL TNSE for 48 h (P<0.05), while Bad, caspase-9 and caspase-3 mRNA levels were upregulated (P<0.05). Moreover, TNSE treatment resulted in downregulation of NF-κB protein expression and strikingly upregulated protein expressions of Bad, cleaved caspase-9, cleaved caspase-3 in a dose-dependent manner, as determined by Western blot.

CONCLUSIONTNSE exhibits significant anti-proliferative and apoptotic effects in Raji cells, which may be involved in regulation of NF-κB and Bad, and activation of caspase-9 and caspase-3.

Apoptosis ; drug effects ; Caspase 3 ; genetics ; metabolism ; Caspase 9 ; genetics ; metabolism ; Cell Proliferation ; drug effects ; Drugs, Chinese Herbal ; pharmacology ; Gene Expression Regulation, Neoplastic ; drug effects ; Humans ; NF-kappa B ; genetics ; metabolism ; Plant Extracts ; pharmacology ; Tumor Cells, Cultured ; bcl-Associated Death Protein ; metabolism

OBJECTIVETo investigate anticancer effect and potential mechanism of tanshinone II(A) (Tan II(A)) on human nasopharyngeal carcinoma cell line CNE cells.

METHODAntiproliferative effect of Tan II(A) on CNE cells was evaluated by morphological examination, cell growth curves, colonial assay and MTT assay. Apoptosis detection was carried out using Hoechest 33258 and PI double-dyeing method. Intracellular Ca2+ concentration and mitochondria membrane potential were detected by fluorospectrophotometer. Bad and MT-1A transcript analysis in CNE cells was analyzed by real-time reverse transcriptase-polymerase chain reaction (RT-PCR).

RESULTTan II(A) could inhibit CNE cells proliferation in dose- and time-dependent manner. 50% inhibiting concentration of Tan II(A) on CNE cells in 24, 48, 72 h was 45.7, 24.8, 3.3 mg x L(-2), respectively. Typical apoptotic morphology such as chromatin aggregation was observed in CNE cells with Tan II(A) treated for 24 h, and the apoptotic inducing effect was in a dose-dependent manner. After treated with Tan II(A), intracellular Ca2+ concentration of CNE cells was increased, mitochondria membrane potential of the cells was decreased, relative mRNA level of Bad and MT-1A was up-regulated.

CONCLUSIONTan II(A) had anticancer effect on CNE cells through apoptosis via calcineurin-dependent pathway and MT-1A downregulation.

Antineoplastic Agents, Phytogenic ; pharmacology ; Apoptosis ; drug effects ; Calcium ; metabolism ; Carcinoma ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Diterpenes, Abietane ; pharmacology ; Drugs, Chinese Herbal ; pharmacology ; Gene Expression Regulation, Neoplastic ; drug effects ; Humans ; Membrane Potential, Mitochondrial ; drug effects ; Metallothionein ; genetics ; Nasopharyngeal Neoplasms ; genetics ; metabolism ; pathology ; Signal Transduction ; drug effects ; bcl-Associated Death Protein ; genetics